Acute Tolerability of Cessation of Deep Brain Stimulation Therapy for Obsessive-Compulsive Disorder Shows Spatial Variability

Introduction: DBS of the ventral capsule (VC) region is an established therapy for treatment resistant OCD (trOCD). Some patients report acute adverse effects when DBS is turned off even briefly, while others appear less affected. This phenomenon remains sparsely documented in the literature, which compelled us to characterize it and investigate potential underlying mechanisms.

Methods: We performed a retrospective review of programming sessions and research tasks in 11 patients who received VC DBS for trOCD at our institution from 2018-2024. In each patient, we noted if they experienced acute adverse effects when DBS was turned off or significantly lowered, such as during impedance testing. Patients were accordingly dichotomized into “tolerant” or “intolerant” categories. We subsequently interviewed patients to further characterize this phenomenon. Finally, we reconstructed patient electrodes in standard space to allow for comparison of the anatomic distribution of electrodes between tolerant and intolerant patients.

Results: Six patients (55%) were found to be acutely intolerant of stimulation loss. This observation was made during stimulation discontinuation trials (3), research tasks involving stimulation cessation (2), or programming sessions (1). Patients primarily described visceral side effects (nausea, abdominal discomfort) that manifested immediately upon cessation of stimulation. Electrode reconstruction revealed that those associated with intolerance were more posteriorly located (p=0.016), typically posterior to the anterior commissure. No significant difference was observed in the superior-inferior or medial-lateral distribution of electrodes (p=0.351 and 0.665, respectively).

Conclusion : We found that a significant proportion of patients receiving VC DBS for trOCD exhibit an acute, visceral intolerance of stimulation loss. These patients had electrodes that are more posteriorly implanted in the VC (typically posterior to the anterior commissure) compared to those who tolerate stimulation loss. This finding may be explained by withdrawal of stimulation from certain neural structures such as the hypothalamus that lie posterior to the VC.